Protective coatings are used over a wide range of substrates to protect the substrate from abrasion, chemicals, stains, sunlight, weather, moisture, heat, cold, and other hazards. A typical protective coating may be derived from thermosetting compositions that are coated onto the desired substrate and then allowed or caused to cure to form the protective coating. One strategy formulates these coating compositions from one or more kinds of particles and other additives dispersed in a free radically polymerizable fluid. PCT Patent Publication WO 02/077109 is exemplifies such coatings.
In particular, protective coatings for engineered flooring materials are highly desired. The industry continues to search for coatings with even better abrasion resistance while still maintaining excellent toughness characteristics. Unfortunately, achieving higher levels of abrasion resistance often involves compromising toughness inasmuch as the chemistry that provides good abrasion resistance tends to reduce toughness unduly and vice versa. For instance, abrasion resistance can be improved by increasing crosslink density, but increasing crosslink density can make coatings more brittle than might be desired. An important industry objective is to search for strategies that would allow high levels of abrasion resistance and toughness to be achieved at the same time.